Deltex Homolog 4 (DTX4)

DTX4 Regulator of Notch signaling, a signaling pathway involved in cell-cell communications that regulates a broad spectrum of cell-fate determinations. Belongs to the Deltex family. 2 isoforms of the human protein are produced by alternative splicing. Deltex is known as a Notch signal mediator, but its physiological action mechanism is poorly understood. Deltex expression was constitutive in resting T cells and was reduced upon T-cell receptor (TCR)-stimulated activation. The biological role of Deltex is supported by the enhanced T-cell activation when Deltex1 was down-regulated by small interfering RNA. Overexpression of Deltex1 suppressed T-cell activation but not the proximal TCR activation events. As RING finger proteins, Deltex family members were recently found to possess ubiquitin-protein isopeptide ligase (E3) activity .